#pragma once
#include <stdint.h>
#include <string_view>
#include <string>

namespace blitz_query_cpp
{
    template <class CrcClass>
    inline constexpr typename CrcClass::ResultType CrcTable(typename CrcClass::ResultType v)
    {
        typedef typename CrcClass::ResultType T;
        const T Msb = T(1) << (sizeof(T) * 8 - 1);
        uint8_t i = 8;
        if (CrcClass::RefIn)
        {
            do
                v = v & 1 ? (v >> 1) ^ CrcClass::RevPoly : v >> 1;
            while (--i);
        }
        else
        {
            v = v << (CrcClass::Width - 8);
            do
                v = v & Msb ? (v << 1) ^ CrcClass::Poly : v << 1;
            while (--i);
        }

        return v;
    }

    template <class CrcClass>
    inline constexpr typename CrcClass::ResultType CrcUpdate(
        char newchar,
        typename CrcClass::ResultType crcval)
    {
        if (CrcClass::RefOut)
        {
            return (crcval >> 8) ^ CrcClass::Table((crcval ^ newchar) & 0xff);
        }
        else
        {
            return CrcClass::Table(newchar ^ (crcval >> (CrcClass::Width - 8))) ^ (crcval << 8);
        }
    }

    template <class CrcClass>
    inline constexpr typename CrcClass::ResultType ComputeCrc(
        const char *message,
        size_t length,
        typename CrcClass::ResultType crc = CrcClass::Init)
    {
        for (size_t i = 0; i < length; i++)
        {
            crc = CrcUpdate<CrcClass>(message[i], crc);
        }
        return crc ^ CrcClass::XorOut;
    }

    constexpr uint32_t ReverseBits(uint32_t arg)
    {
        const uint32_t t1 = ((arg >> 1) & 0x55555555) | ((arg & 0x55555555) << 1);
        const uint32_t t2 = ((t1 >> 2) & 0x33333333) | ((t1 & 0x33333333) << 2);
        const uint32_t t3 = ((t2 >> 4) & 0x0F0F0F0F) | ((t2 & 0x0F0F0F0F) << 4);
        const uint32_t t4 = ((t3 >> 8) & 0x00FF00FF) | ((t3 & 0x00FF00FF) << 8);
        const uint32_t value = (t4 >> 16) | (t4 << 16);
        return value;
    }

    constexpr uint32_t Crc32Table[256] =
        {
            0x0,
            0x77073096,
            0xee0e612c,
            0x990951ba,
            0x76dc419,
            0x706af48f,
            0xe963a535,
            0x9e6495a3,
            0xedb8832,
            0x79dcb8a4,
            0xe0d5e91e,
            0x97d2d988,
            0x9b64c2b,
            0x7eb17cbd,
            0xe7b82d07,
            0x90bf1d91,
            0x1db71064,
            0x6ab020f2,
            0xf3b97148,
            0x84be41de,
            0x1adad47d,
            0x6ddde4eb,
            0xf4d4b551,
            0x83d385c7,
            0x136c9856,
            0x646ba8c0,
            0xfd62f97a,
            0x8a65c9ec,
            0x14015c4f,
            0x63066cd9,
            0xfa0f3d63,
            0x8d080df5,
            0x3b6e20c8,
            0x4c69105e,
            0xd56041e4,
            0xa2677172,
            0x3c03e4d1,
            0x4b04d447,
            0xd20d85fd,
            0xa50ab56b,
            0x35b5a8fa,
            0x42b2986c,
            0xdbbbc9d6,
            0xacbcf940,
            0x32d86ce3,
            0x45df5c75,
            0xdcd60dcf,
            0xabd13d59,
            0x26d930ac,
            0x51de003a,
            0xc8d75180,
            0xbfd06116,
            0x21b4f4b5,
            0x56b3c423,
            0xcfba9599,
            0xb8bda50f,
            0x2802b89e,
            0x5f058808,
            0xc60cd9b2,
            0xb10be924,
            0x2f6f7c87,
            0x58684c11,
            0xc1611dab,
            0xb6662d3d,
            0x76dc4190,
            0x1db7106,
            0x98d220bc,
            0xefd5102a,
            0x71b18589,
            0x6b6b51f,
            0x9fbfe4a5,
            0xe8b8d433,
            0x7807c9a2,
            0xf00f934,
            0x9609a88e,
            0xe10e9818,
            0x7f6a0dbb,
            0x86d3d2d,
            0x91646c97,
            0xe6635c01,
            0x6b6b51f4,
            0x1c6c6162,
            0x856530d8,
            0xf262004e,
            0x6c0695ed,
            0x1b01a57b,
            0x8208f4c1,
            0xf50fc457,
            0x65b0d9c6,
            0x12b7e950,
            0x8bbeb8ea,
            0xfcb9887c,
            0x62dd1ddf,
            0x15da2d49,
            0x8cd37cf3,
            0xfbd44c65,
            0x4db26158,
            0x3ab551ce,
            0xa3bc0074,
            0xd4bb30e2,
            0x4adfa541,
            0x3dd895d7,
            0xa4d1c46d,
            0xd3d6f4fb,
            0x4369e96a,
            0x346ed9fc,
            0xad678846,
            0xda60b8d0,
            0x44042d73,
            0x33031de5,
            0xaa0a4c5f,
            0xdd0d7cc9,
            0x5005713c,
            0x270241aa,
            0xbe0b1010,
            0xc90c2086,
            0x5768b525,
            0x206f85b3,
            0xb966d409,
            0xce61e49f,
            0x5edef90e,
            0x29d9c998,
            0xb0d09822,
            0xc7d7a8b4,
            0x59b33d17,
            0x2eb40d81,
            0xb7bd5c3b,
            0xc0ba6cad,
            0xedb88320,
            0x9abfb3b6,
            0x3b6e20c,
            0x74b1d29a,
            0xead54739,
            0x9dd277af,
            0x4db2615,
            0x73dc1683,
            0xe3630b12,
            0x94643b84,
            0xd6d6a3e,
            0x7a6a5aa8,
            0xe40ecf0b,
            0x9309ff9d,
            0xa00ae27,
            0x7d079eb1,
            0xf00f9344,
            0x8708a3d2,
            0x1e01f268,
            0x6906c2fe,
            0xf762575d,
            0x806567cb,
            0x196c3671,
            0x6e6b06e7,
            0xfed41b76,
            0x89d32be0,
            0x10da7a5a,
            0x67dd4acc,
            0xf9b9df6f,
            0x8ebeeff9,
            0x17b7be43,
            0x60b08ed5,
            0xd6d6a3e8,
            0xa1d1937e,
            0x38d8c2c4,
            0x4fdff252,
            0xd1bb67f1,
            0xa6bc5767,
            0x3fb506dd,
            0x48b2364b,
            0xd80d2bda,
            0xaf0a1b4c,
            0x36034af6,
            0x41047a60,
            0xdf60efc3,
            0xa867df55,
            0x316e8eef,
            0x4669be79,
            0xcb61b38c,
            0xbc66831a,
            0x256fd2a0,
            0x5268e236,
            0xcc0c7795,
            0xbb0b4703,
            0x220216b9,
            0x5505262f,
            0xc5ba3bbe,
            0xb2bd0b28,
            0x2bb45a92,
            0x5cb36a04,
            0xc2d7ffa7,
            0xb5d0cf31,
            0x2cd99e8b,
            0x5bdeae1d,
            0x9b64c2b0,
            0xec63f226,
            0x756aa39c,
            0x26d930a,
            0x9c0906a9,
            0xeb0e363f,
            0x72076785,
            0x5005713,
            0x95bf4a82,
            0xe2b87a14,
            0x7bb12bae,
            0xcb61b38,
            0x92d28e9b,
            0xe5d5be0d,
            0x7cdcefb7,
            0xbdbdf21,
            0x86d3d2d4,
            0xf1d4e242,
            0x68ddb3f8,
            0x1fda836e,
            0x81be16cd,
            0xf6b9265b,
            0x6fb077e1,
            0x18b74777,
            0x88085ae6,
            0xff0f6a70,
            0x66063bca,
            0x11010b5c,
            0x8f659eff,
            0xf862ae69,
            0x616bffd3,
            0x166ccf45,
            0xa00ae278,
            0xd70dd2ee,
            0x4e048354,
            0x3903b3c2,
            0xa7672661,
            0xd06016f7,
            0x4969474d,
            0x3e6e77db,
            0xaed16a4a,
            0xd9d65adc,
            0x40df0b66,
            0x37d83bf0,
            0xa9bcae53,
            0xdebb9ec5,
            0x47b2cf7f,
            0x30b5ffe9,
            0xbdbdf21c,
            0xcabac28a,
            0x53b39330,
            0x24b4a3a6,
            0xbad03605,
            0xcdd70693,
            0x54de5729,
            0x23d967bf,
            0xb3667a2e,
            0xc4614ab8,
            0x5d681b02,
            0x2a6f2b94,
            0xb40bbe37,
            0xc30c8ea1,
            0x5a05df1b,
            0x2d02ef8d,
    };

    struct Crc32
    {
        typedef uint32_t ResultType;
        static constexpr unsigned Width = 32;
        static constexpr ResultType Poly = 0x04C11DB7UL;
        static constexpr ResultType Init = 0XFFFFFFFFUL;
        static constexpr bool RefIn = true;
        static constexpr bool RefOut = true;
        static constexpr ResultType XorOut = 0XFFFFFFFFUL;
        static constexpr ResultType Check = 0xCBF43926UL;
        static inline constexpr const char *CheckMessage() { return "123456789"; }
        static inline constexpr const char *Name() { return "CRC 32"; }
        static constexpr ResultType RevPoly = ReverseBits(Poly);
        static inline constexpr ResultType Table(ResultType v) { return CrcTable<Crc32>(v); }
    };

    struct Crc32WithTable
    {
        typedef uint32_t ResultType;
        static constexpr unsigned Width = 32;
        static constexpr ResultType Poly = 0x04C11DB7UL;
        static constexpr ResultType Init = 0XFFFFFFFFUL;
        static constexpr bool RefIn = true;
        static constexpr bool RefOut = true;
        static constexpr ResultType XorOut = 0XFFFFFFFFUL;
        static constexpr ResultType Check = 0xCBF43926UL;
        static inline constexpr const char *CheckMessage() { return "123456789"; }
        static inline constexpr const char *Name() { return "CRC 32"; }
        static constexpr ResultType RevPoly = ReverseBits(Poly);
        static inline constexpr ResultType Table(ResultType v) { return Crc32Table[v]; }
    };

    constexpr uint32_t hash_crc32(const std::string_view str)
    {
        return ComputeCrc<Crc32WithTable>(str.data(), str.size());
    }

    constexpr uint32_t operator""_crc32(const char *str, size_t size)
    {
        return ComputeCrc<Crc32WithTable>(str, size);
    }

}